De-Aged
by The Bibliomaniac
Summary: The Doctor and Jack have fallen into trouble and now they're children! Does the secret to regaining their age lie within the walls of Hogwarts?
1. Chapter 1

Disclaimer: I do not own Doctor Who or Harry Potter. I am not that awesome.

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Chapter 1

"Jack, hurry up!" The Doctor ran for the TARDIS, fumbling with his key.

"Doctor, wait! I don't understand," Jack shouted. "The gun, it didn't do anything."

"The effects won't become apparent yet; they increase exponentially." The Doctor ushered Jack inside and then charged down a corridor. Jack shrugged and followed. After a few minutes, he was thoroughly lost. In all his time travelling with the Doctor, he never explored more than the corridors immediately adjacent to the control room; there had never been any need, everything Jack wanted or needed was right there.

"Here, here, here!" shouted the Doctor and threw himself through a door. Jack followed and found himself in some sort of lab. The Doctor was scrambling, pulling chemicals out of cabinets and hastily measuring them out before dumping them into beakers.

"Doctor, what is going on?"

"That blast, the gun… it's a de-ager. Literally youths you out of existence," the Doctor explained, still mixing chemicals. "It's a favorite of special ops teams and assassins because it doesn't leave a body."

"And you're doing… what?" asked Jack, watching the Doctor stirring the contents of two beakers, one with each hand.

"Stopping the de-aging. Here," he thrust one of the beakers into Jack's hand, "drink this." The Doctor took his beaker and gulped it down, grimacing at the taste. Jack followed suit and was pleasantly surprised by the light flavoring of pears.

"So we're fine now?" he asked. At that moment, there was a loud popping noise and a burst of light. Jack looked around, blinking. Much to his astonishment, the Doctor, standing before him, looked like the original Doctor. That is, the first Doctor Jack had met. "Uh, Doctor, I don't think it worked. You're all ears and nose again."

"Of course I am," he replied in his old, thick Northern accent. "No, the mixture we just drank worked perfectly." He started mixing more chemicals together. He paused for a moment in thought, then reached into his pocket and pulled out his glasses and started working again. "It wasn't to get us to stop de-aging, I'm starting that one now. No, that was to preserve our personalities."

"What?"

The Doctor turned to Jack, an eyebrow raised. Jack had to stop himself from laughing out; it was way too surreal seeing his original Doctor still wearing a pinstripe suit (that was too small for him now) and thick plastic glasses. "The mixture I'm making now will take at least an hour to make. By that time, you'll probably have de-aged till before you met Rose and me, you'll possibly even have de-aged until the point you were still working for the Time Agency. You'll still know me, the gun doesn't remove memories, but from what you've told me, and what I know of the Time Agency, it won't matter; your personality would be so different, it would seem like we're strangers.

"I, on the other hand, will continue to de-age and swap bodies, each time for the previous regeneration. I always loved who I was at the time, but with hindsight, I know that some of them were difficult to get a long with, and they all had different preferences for preparing chemicals. I'd rather not be interrupted and have to start basically from scratch every time that happens."

Jack nodded his understanding and the Doctor got on with his work. In the time waiting, Jack got to see a reverse history of the Doctor's regenerations. Every so often, there was a pop, a flash of light, and a different man standing, mixing chemicals. He was a fair-haired, youngish looking fellow when Jack suddenly felt horribly ill and started glowing faintly. "Doc…" he groaned.

The Doctor turned from the distillery he was working to look at Jack. "You're fine. That's just the effects of Bad Wolf. So far, you've been stuck at the same age, when she changed you, because you had lived so long. You'll start de-aging in true now." The Doctor suddenly grunted and turned away, biting his lip and wrapping both arms around his middle.

"You okay?" Jack asked, approaching to help.

"Stay back," the Doctor snapped. "You're the problem. You're still a fixed point in time… but you're also changing. It's a paradox, but a weird one. It's playing havoc on my senses." As if in agreement, the TARDIS shook slightly. "Listen, the TARDIS just moved the Zero closet to across the hall from this room. Kindly get in there before you drive her and me mad." Jack frowned, but did as the Doctor bid, leaving the room and going through the door directly in front of him.

The room _was_ a closet, with barely enough room for Jack to stand in. Despite the cramped space, there was something calming about the room, and Jack felt muscles he didn't even know were clenched slowly relaxing. There was a slight humming noise suddenly and Jack could hear the Doctor's voice.

"Sorry, it took me a moment to remember how to access the room's speakers. Well, the almost-speakers, I should say, since there aren't any real speakers. It's really just my mental projection resonating in the room. You won't be able to respond I'm afraid." The voice sounded like the Doctor Jack knew, the skinny one with stick-up hair. He supposed it made sense, if the voice were his mental voice.

He realized the Doctor was still talking. "…fifteen minutes, half an hour max," said the voice. "Hopefully we won't be _too_ de-aged. Sorry about the size of the Zero closet, by the way. It used to be a full room, but it got ejected a few years ago. Well, I say a few years, I really mean a few decades. Well, I mean centuries actually. The point is, I had the TARDIS start growing one as soon as the crisis was over and I remembered I lost it. But it's a complete energy null space. It's perfectly isolated from the rest of the universe, so it takes a while to grow one. I'm amazed we even have a closet already."

A few more minutes passed, and the Zero room door opened. A severe looking young man was standing in front of him, proffering a beaker filled with a fizzing liquid. "Oh dear, you've become a teenager. No matter. Here, drink this." Jack grabbed the beaker and chugged down the liquid. Unlike the first one, this one was bitter and vile to the taste.

He grimaced and asked, "So what body are you on now? You look really young, considering the general theme had seemed to be you getting older looking as you got younger."

The Doctor frowned. "I've been in my first body for a few minutes now. It's not that I've degenerated into a young body. This form started out quite old. I've de-aged to this point. You're looking at me when I was only about 25 years old."

Jack suddenly lost a foot of height. "That was a growth spurt for your information," the Doctor said.

"Wait, we're still de-aging?" Jack asked in a panic.

"Yes," the Doctor replied, pulling out a pocket mirror and inspecting his face, which Jack noticed was younger looking than before. "I'm around 18 to 20 now." Seeing Jack's panicked face, he smiled sadly. "I did the best I could. It was more important to get the solution made than to have it perfect. Hopefully what I made will be enough."

"I don't…" Jack felt another few inches disappear, "understand," he finished.

"The solution has slowed our rates of de-aging, eventually we'll stop. But it wasn't pure, so we've got a little bit more de-aging before us. Hopefully it will be before our brains have de-aged to the point where the first mixture was useless."

"What?!" Jack yelped as he felt another 'growth spurt' leave him.

"Well, if our brains de-develop, it doesn't matter how preserved our personality was, there won't be enough brain for it to remain. Cheer up, though," he smiled, "you seem to have stopped. Around eleven, I would hazard to guess," he added.

Jack pouted. He didn't like being an eleven year old again. Not to mention, there was the very big concern that an eleven year old's brain was much less complete that an adults, so it was already quite possible that he was already different.

As he was trying to figure out a test to see how immature he was now, the Doctor suddenly plummeted one and a half feet. He cursed. Judging by the lack of a translation, Jack guessed it was Gallifreyan. "That was my 14 year old growth spurt." There was another, smaller drop. "And that was my 12 year old one. I really hope this stops soon." It could have been his imagination, but Jack thought he heard a quiver in the Doctor's voice.

A few more inches disappeared, and suddenly, Jack was taller than his friend. They both waited, but after a few minutes, it was clear the Time Lord's de-aging had finally stopped as well. The Doctor pulled out his mirror again. "Hm. About eleven, I should guess. Funny how we've both ended up at the same age." The Doctor grinned and shoved the mirror into the pocket of his now too-big pants. "Come on, let's see about reversing the effects."

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A/N: This is my baby. I've been writing it for a while now. I've got a nice buffer of chapters, but I'm not publishing them all at once because I am really inconsistant at writing and need said buffer. Your best bet to know my schedule for updates will be to just follow the story, since I'm not sure what my schedule will be.

This story is literally the longest thing I've ever written (research papers for school aside). I would really appreciate (critical) feedback. I hope you enjoyed the first chapter!

**Sorry if you're getting an alert for this; there's no new chapter today. There was a slight grammatical error (you're ≠ your) that I could not leave alone.**

~Bibliomaniac


	2. Chapter 2

**Guess what?! It's 2 weeks later, which was when I told myself I could update again (I've been holding myself back, reminding myself that there wouldn't be a buffer if I updated all at once). I'm so happy and excited that people have liked this so far! Please read the author's note at the end of the chapter!**

Chapter 2

"So just to clarify, there is something you don't know, and none of your books are helping?" Jack grinned as the Doctor angrily shoved another pile of books away; they were all useless!

"Shut it, Jack!" the Doctor snapped. "It's not like I've ever dealt with this problem, and I can't think straight!" He rapped at his head with both hands. "It's this stupid, tiny, little brain. It's not good enough!" he ended in a scream.

"Pleasant child you were," quipped Jack. "Besides," he added, "what's the big deal? My brain's shrunk too, and I'm not having too much difficulty remembering stuff."

"Ugh, please. You've got all your experiences crammed in your brain. That's it. It's not too bad. I've got all my experiences as well as the knowledge of all that is, all that was, and all that could ever be shoved in there as well. When I was a child, it took me years to unravel the knowledge, mainly because my brain wasn't developed enough to handle it. I've got a huge headache from all this knowledge I'm not supposed to have, and you're not helping! You with your 'fixed-but-not-fixed' nature. Rassilon!" he swore, "I'm not even supposed to be able to sense stuff like that yet!"

Jack was quiet. The Doctor was always so closed about Time Lord society; he had no idea how to help. The Doctor took a deep breath and seemed to calm down. "I'm sorry," he said, "I had a rather explosive temper as a child, it seems to be leaking through. I think the best way to deal with the problem is to shut out some non-essential knowledge and abilities."

"And how is that done exactly?"

"I need to meditate for a bit. Do me a favor: just keep looking around the library. I know I have a book detailing the re-aging process somewhere, most likely in this section or the one next to us." Jack nodded and the Doctor settled down into a more comfortable position.

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Some time later, the Doctor opened his eyes to find Jack sitting, grinning, in front of him. "I found the book," he declared. "How're you feeling?"

"Better," the Doctor admitted. "A bit blind though. I wound up shutting down my ability to sense time and location accurately, which includes the ability to sense paradoxes such as yourself, and I've lost some major chunks of history, but otherwise, I think managed to keep everything. So let's see the book."

Jack slid an open book towards the Doctor and pointed a finger at the page. "Right there."

The Doctor accepted the book and carefully read the proper passage. He frowned. "What's wrong, Doctor?"

"The proper chemical composition is toxic to humans," he started.

"I'm immortal, remember?"

"Yeah, but after you die and come back, you'd still be de-aged."

"Oh… what about you?"

"That's the other problem. It would re-age me, but that wouldn't include the regenerations. I'd die of old age or radiation poisoning or whatever it was I had to regenerate from in the first place."

"Can't remember?" joked Jack.

"I don't think I ever figured it out, even back then."

Jack barked out a laugh. "So what do we do now?"

"Well…" the Doctor rubbed the back of his neck in thought. "Even if I can't feel how wrong you are, the TARDIS can, and she's upset about it. We should land somewhere and find a place to stay until I can figure out a way to adapt the treatment."

"Where are we going to stay where questions won't be asked?"

"I don't know!" snapped the Doctor. He paused to take a deep breath, calming and collecting himself. "I'll set the controls for Earth and some time in the 20th century. The TARDIS can work out the details. She's usually good about that sort of thing."

* * *

The TARDIS landed heavily. Flights in the time capsule were never smooth, but with the Doctor too small to reach all the controls fast enough, the flight was especially rough. Jack pulled himself off the ground and jumped for the door. "Let's see where we are," he said.

"Hold on," said the Doctor. "If we're lucky, the TARDIS might…" there was a small ding and two letters slid out of a slot on the consol. "Yep, she's found us a cover story. Thank you, old girl." He patted to consol gently.

Jack grabbed the letter that said his name on it.

Mr. J. Harkness

Consol Room

TARDIS

London

It was so oddly specific. He shrugged and tore it open.

Hogwarts School of Witchcraft and Wizardry

Headmaster: Albus Dumbledore (Order of Merlin, First Class, Grand Sorc., Chf. Warlock, Supreme Mugwump, International Confed. of Wizards)

Dear Mr. Harkness,

We are please to inform you that you have been accepted at Hogwarts School of Witchcraft and Wizardry. Please find enclosed a list of all necessary books and equipment. Term begins on September 1. We await your owl by no later than July 31.

Yours sincerely,

Minerva McGonagall,

Deputy Headmistress.

(Woo! Cue theme music!)

**A/N: So yeah... first off, you'll notice this is a bit shorter than last chapter. This will be about the length of most chapters here on out. Sorry! **

**Thank you all for your awesome reviews. One person (Pelahnar) asked what the Doctor looks like as a kid. Since I never actually describe him in the story, I decided to put it here: if you do a search on William Hartnell young, you get a few pictures of him in his early 20s. Imagine that face, but younger and not ginger (apparently the first actor for the Doctor was a red head, who knew!). **

**Please review!**


	3. Chapter 3

Chapter 3

Jack swung his arms back and forth, trying to stay warm. It was dark, drizzling, and just chilly enough that Jack was miserable. The Doctor had all but shoved him out of the TARDIS wearing naught but a thin tee shirt and jeans. The weather might be fine for Doctor I-can-survive-even-the-cold-of-space-for-limited-a mounts-of-time-because-I'm-a-Time-Lord, but one day, somebody would have to sit down and explain to him that humans generally liked a light jacket when the temperature was below 20˚C.

He did not even know why they were here. The Doctor landed, pushed Jack out the door, and disappeared back inside without a further word. "I swear if you try to leave without me again, I'll grab onto the TARDIS and never let go," muttered Jack. At that moment, the door swung open. A heavy trunk was shoved out. The door closed again. Jack inspected the trunk. It was a standard build, nothing special about it. It did say "Jack" on it in very nice lettering though.

Jack opened it. At first he was confused. It looked bigger on the outside. That's a change, he thought. Then he realized there was a false bottom. The top layer had what Jack assumed was school supplies and clothing. He carefully removed it. Without the false bottom, the trunk was a bit bigger. Actually, it was a lot bigger. Like all Time Lord storage things, it was bigger on the inside than the outside. There were several extra cubic meters of storage space, filled with gadgets and devices, most of which were Jack's favorites on the TARDIS. There was also a large pile of gold, silver, and bronze pieces with a short note explaining the conversion rates between them and the British Pound.

Jack pulled out what he deemed a sufficient amount of money and put the top layer back into the trunk. As he closed it, the TARDIS door opened again. "Put this on," called the Doctor, and a black cloth was thrown at Jack. As Jack figured out that it was a robe, the Doctor pushed another trunk out the TARDIS. He was already wearing a dapper set of robes. When the trunk was outside the TARDIS, the Doctor went back in, but came out almost immediately, holding a small beaker. "Drink this," he said, offering it to Jack.

"What is it?" asked Jack, smoothing the robes down and taking the beaker.

"The ability to use magic is really just a heightened sensitivity to a psionic field. The field fades out of existence by the 51st century, which is why you lot don't have magic. The ability remains, however. Quite powerfully too, I believe. You just have to wake it up a bit. Think of this as a light stimulus."

"Anything in it I should know about?" Jack asked, sniffing it cautiously. It was bubbling for heaven's sake!

"A little lysergic acid diethylamide, but not enough to cause any problems. Just avoid any drug tests for a while. Now drink it," insisted the Doctor.

Jack rolled his eyes. The question was how much did he trust the Doctor? The answer: Jack downed the concoction in one gulp. The Doctor was right; there wasn't enough LSD to cause a problem; Jack had played around enough in the 70's to know his limits with the drug. "Now what?" he asked.

"Look over there." The Doctor gestured.

Jack turned to look. "Woah! Was that inn always there?"

"Yes. It's called the Leaky Cauldron. It had a light perception field on it to keep away non magic people." The Doctor sniffed. Clearly, he did not approve of segregating magical from non magical. "Well, Jack, allons-y! We'll get a room in the inn and get wands tomorrow. Then there's nothing to do but wait."

"Why wait? We could just jump ahead to September 1st."

"The TARDIS has made it known in no uncertain terms that she isn't taking you anywhere until you're no longer as paradoxical," the Doctor grumbled. Jack opened his mouth to protest. "Believe me, I don't like it either," the Doctor said before Jack had a chance to say anything. "But I don't always make the rules."

"Fine then. Where's she going to be until September 1st? She can't exactly stay here in the middle of the street."

"Well, she could… perception filter, remember? But no. I'm sending her to the outskirts of the school. She'll be there when we need her." The Doctor turned to face the TARDIS. "Oh, I learned a new trick. Watch." He stared at the TARDIS with an intense look of concentration on his face. Jack was about to ask what he should be watching for, when the Doctor snapped. The TARDIS started to vwarp and very quickly disappeared. "It's a lot easier when I just open the doors with a snap. Turning on the circuits takes a little more focus," the Doctor explained.

Jack rolled his eyes and headed for the inn, dragging his trunk behind him.

**Sorry it's so short; I might post the next chapter earlier to make up for it. Thank you for all your positive reviews; they really make my day :)**

**Please review, favorite, and/or follow!**


	4. Chapter 4

**Hello! As I said, I'm posting early because last chapter was a bit short, so is this one. There is an A/N at the end, but I wanted to put this here (it was important enough to me that when I wrote the chapter, I embedded it in the actual document!): **

**This story will NOT have Doctor/Jack slash. Jack and someone else, who knows. But anything that could be something between Jack and the Doctor is pure fluff, despite Jack's wishes. If you want to squint and see something, be my guest. But it is not intentional.**

Chapter 4

The innkeeper had been a bit surprised to find two young boys traveling on their own; nevertheless he set them up in a comfortable room and even carried their trunks up for them. On the way up, Jack snagged a discarded newspaper.

Rule 6 of the Time Agency: any time you are establishing yourself in a new time or space, catch up on current events. Sub-rule A: newspapers were your best bet. Sub-rule B: if you're in a time or place that doesn't have newspapers, going to a bar and listening for a few hours is the best you're going to get. Sub-rule C: don't let anyone know that you don't know current events.

Thus was how Jack wound up relaxing on the bed, reading a strange newspaper with moving pictures while the Doctor played jacks on the floor. Jack finished the paper and turned to look at the photo on the front again. "Doctor," Jack started. He looked over the top of his paper to glance at his friend. The Doctor, having gotten bored of jacks, was now trying to balance the jacks on top of each other to build a tower. He gave no indication that he heard. "Doctor," Jack said again louder. The Doctor looked up, slightly startled. "How much do you know about this time period?"

The Time Lord returned to building his tower. At first, Jack thought he was not going to answer, but finally: "Not as much as I should. Something tells me this is a very important time, rife with fixed points, but… I can't think of anything."

"Why not?" asked Jack, pushing himself off the bed slightly, concerned.

"I think I cut off more than I originally thought. That's the problem with self-induced, specific amnesia: there's no way to know what you actually cut out. I may have lost more history than I intended." The Doctor paused, frowning. "At the time, I obviously thought it was necessary, otherwise I'd be reopening the memories and resorting them." He looked up at Jack and smiled. "Why do you ask?"

"There's a murderer on the loose…"

"Sirius Black," interrupted the Doctor.

"So you know?" asked Jack. "You know this part of time?"

The Doctor took a deep breath and looked down at his tower, thinking. "Not exactly. There are trigger words that I left so that I could fit in properly, I think."

"So if I were to say the name Harry Potter, you would tell me… what?"

"Harry Potter is the sole survivor of what is known as the killing curse. He is considered a savior of the wizarding world for defeating a dark wizard known as Voldemort."

Jack nodded. "Well, that agrees with what the paper says."

"There's more…" continued the Doctor. "I know it's important. I know he's connected with some of the fixed points, but I really cannot remember." Jack stared at the Doctor slightly worried. The Doctor smiled, ignoring Jack's concern, then yawned and stretched. "We should probably get some sleep," he said.

Jack blinked perhaps half a dozen times. "Are you feeling alright?" he finally asked.

"Fine, why?" The Doctor yawned again and stood up.

"I have _never_ seen you sleep, unless you were very sick."

"Younger body, and my brain is redeveloping. For children of Gallifrey, youth is like one long drawn out regeneration. Instead of needing say forty-eight hours of uninterrupted sleep, I need a few hours a week, starting tonight I think."

"When you say a few hours…"

"No more than four a week. Now move," the Doctor commanded. Jack shuffled off the bed, just in time for the Doctor to collapse on it.

"Doctor," said Jack. There was no response. "Doc," he said again, prodding the prone figure. The Doctor gave a loud snore.

Jack weighed his options. He slept much less as an immortal than he ever did before (excepting when he had just experienced a particularly brutal death). So theoretically he could keep watch. However, even if he did not need to sleep, he enjoyed it. It gave his brain a chance to freshen up. Moreover, now that the Doctor had mentioned sleep, he felt exhausted as well. Perhaps, like the Doctor, his brain was regrowing as well. It meant, like other eleven-year-old humans, he would need about eight hours of sleep a day.

Jack looked at the bed. It was a double, yet the Doctor managed to take up the entire thing. Jack reached over and pushed and pulled the Doctor onto one side of the bed. He then tugged the blankets out from under the Doctor. Finally, he crawled into the now very disheveled bed. As he tried to get settled, the Doctor rolled over and grabbed Jack in a hug.

Jack froze. Ever since he had become immortal, any physical contact between the two time travelers was always instigated by Jack, and it was always brief and always uncomfortable for the Doctor. As Jack worried about what he should do, the Doctor snuggled closer until the two of them were spooning. At this point, all thoughts of propriety left Jack's mind and he let himself go in the ecstasy of a cuddle.

**A/N: Firstly, I'd like to apologize if you got odd updates messages; I was looking something over, and I noticed one or two "your/you're" mistakes which have since been corrected. **

**Answer to questions: Does the Doctor/Jack still remember the Harry Potter books? No. I'll be pretending this is an AU in which the Harry Potter books were never written. JK Rowling made her fame and fortune writing a very successful series of young adult fantasy books about a young animagus who could turn into a small aquatic mammal of the weasel family. They were called 'Hairy Otter' (he had to defeat an evil toad animagus called Moldy Warts)... **

**If you're still not sure which book this takes place in, continue reading. In a few chapters it will become obscenely clear.**

**Thank you all for your positive reviews. They are awesome!**


	5. Chapter 5

Chapter 5

Jack awoke slowly, feeling better than he had in ages. He yawned widely and stretched, working every muscle he could in the position he was in. Finally he opened his eyes. No Doctor. He rolled over to inspect the rest of the room. No Doctor. "Doctor?" he called out.

"In here," came a muffled response. Jack looked wildly around until he saw the Doctor's trunk was open. He pulled himself out of bed and approached the trunk. Like his own, there was a false bottom that had been removed. Unlike his own, it did not have a somewhat deeper bottom. No, it had an entire room underneath. He only had a small view of the room. As he looked, the Doctor walked across his field of vision. The Doctor looked up and saw Jack peering down. "Come on down," he said.

On the left side of the trunk, there was a small spiral staircase. Jack swung himself into the trunk and onto the ladder. As he climbed down, he realized the room was really not that big, but it was large enough to contain a full lab. "What's all this?" asked Jack.

"I couldn't bring the whole TARDIS, but I didn't want to be cut off completely. This was the biggest trunk I could find to put stuff in. I've got a little biology over in that corner," he gestured, "including an emergency medical kit. Over there," he pointed behind him, "is all chemistry. That wall houses every book I could grab about aging and de-aging as well as some of my personal favorite books." He shrugged. They were probably going to be stuck as they were for a while, might as well have his books with them. "I also have some history books, but not as many as I wanted. The rest of the lab is miscellaneous, a little of everything else. The main point of the lab is to get us back to normal, of course."

"Of course."

"Additionally, we'll be at Hogwarts. It has a huge library, one of the largest in Britain, and the professors are some of the best magic scientists in the world. Between this lab and the school, we shouldn't have much of a problem." Jack nodded his understanding. "Now, as I'm sure you noticed, you have a few tools, to use at your discretion. Hogwarts is a boarding school, and we might not be in the same room, so I want you to have your own equipment just in case."

"Wait a second," interrupted Jack. "Why don't we just tell whoever is in charge our situation? It seems easier than masquerading as kids and going to school."

The Doctor pursed his lips and inhaled deeply, trying to come up with a reason. "Other than gut instinct? Um… I know there's a reason I wanted to be as incognito as possible…" he gestured vaguely, trying to come up with an explanation.

Jack smirked and held up a hand. Obvious a bit more of his childhood was leaking through if he was having difficulty expressing himself. "Look, Doctor, if you've got a gut feeling against it… I've learned to trust those." The Doctor stopped gesticulating and let out a sigh of relief that he would not have to explain further. "How incognito are we going?"

"Don't let people know you're not eleven, don't let people know you're immortal, don't let people know you time travel or are from the 51st century. Keep information about me down to a minimum. I'll be under the name John Smith, by the way. And Jack," the Doctor fixed him with a severe glare, "please remember you are an eleven-year-old in the 20th century. No flirting!"

Jack grinned. "Not even a little?" The Doctor did not even bother trying to respond. He just glared further. "All right, all right." Jack raised his hands in a mock surrender. The Doctor continued his piercing glare. "You mentioned wands last night?" asked Jack, trying to distract the Doctor.

It worked like a charm. "Yes," said the Doctor, rushing for the staircase. "Come. As I'm sure you noticed from the newspaper, we actually only have a few days before September 1st. The sooner we get the wands, the sooner we can get accustomed to them."

**A/N: Good morrow! I am delighted that you all are enjoying the story so far. Sorry this is another short chapter... but I'd rather short and well crafted to long and tedious. Anyway, please review!**


	6. Chapter 6

Chapter 6

Jack was not sure he liked Mr. Olivander. They guy NEVER blinked. What, was his mother one of the fish-like Hath or something? He was a wellspring of information though. Jack went through the newly learned facts in his head: three types of cores, phoenix, unicorn hair, dragonheart; there were other types available, but these seemed to work best; many types of wood, each with their own properties; the wand chooses the wizard.

The Doctor, in his never ending quest for knowledge, started up a fairly detailed conversation with Mr. Olivander while Jack was being measured. "A moment, please," the man finally asked the Doctor. He turned to Jack. "Now, Mr. Harkness, try this wand. It's unicorn and beech." He proffered said wand. Before Jack even got a chance to adjust his grip though, Olivander snatched it away. "No, no. You are not unicorn at all." He jumped to a different side of the room. He started pulling out a wand box, then paused and turned to study Jack a little more. He nodded to himself and continued pulling out the wand. "Dragonheart, definitely. Here is dragonheart and sycamore."

Jack waved the wand around a bit. Olivander frowned. "It seems to appreciate you, but that is not the first choice I would pick for you. Let's see if we can get a more perfect fit." What followed next was a blur to Jack: wands being thrust at him with a brief description then snatched away before he could blink. The Doctor sat in a corner, sulking that he could not ask any more questions at the time.

Finally: "Dragonheart and yew, Mr. Harkness. Ten inches exactly. Somewhat stiff. A very powerful wand, I must say. Good for counter-curses and jinxes, and other forms of defense against the Dark Arts," he paused. "Of course, if a wand is good at defense in a certain type of magic, it is almost certainly as effective at that magic as well." Olivander frowned. "I would hope that you do not fall prey to the Dark Arts though." Jack met Olivander's eyes. The pressure built as they stared at each other. It was almost as if the man knew Jack was little more than a reformed rogue.

The Doctor cleared his throat, and the pressure vanished. "That will be eight galleons, Mr. Harkness." Jack handed over the money and stuck his wand in his pocket. He then made room for the Doctor.

"Ah yes, Mr. Smith was it? Which is your wand hand?"

"Ambidextrous," said the Doctor.

"You would be," muttered Jack. Seriously, he thought to himself, the Doctor may be the universe's best attempt at making a real life Gary Stu.

The Doctor glared at Jack. "I suppose I'll go right handed for this, though. It seems it would be easier." Olivander inclined his head in confirmation.

"Try this wand." The shopkeeper passed over a wand. He was about to start describing the wand when it exploded. All three people in the shop stared for a moment at the smoldering remains of the wand for a second. "Not unicorn hair, then," Olivander calmly, all things considered.

"I'm sorry," said the Doctor, inspecting the charred wood in his hand.

"Not at all. You are hardly the first to destroy a wand in my shop, and you won't be the last. I should warn you against picking up other people's wands though. There shouldn't be a problem with a bonded wand, but do be careful. Certainly don't handle a unicorn hair wand while you are feeling particularly stressed, though." Olivander smiled. "Now let's see. This actually gives me a good sense of what you need."

"How do you mean?" asked the Doctor, as Mr. Olivander climbed a ladder to get at a wand.

"The explosion pattern is fairly specific. My great-uncle spent his life categorizing wand explosions and what they mean. If only everyone who walked into my shop exploded their first wand, I would save hours of time a day." He came down the ladder, holding a wand box. "I'm afraid this wand is a bit expensive. I spent a lot of time working on it. Phoenix feather and sycamore, eight and a half inches, fairly springy. Very good for charms. You'll find you'll have much better results if you keep an open mind in life. Also, be aware that sycamore likes adventure. It might start giving you problems if your life becomes too sedentary." He looked at the Doctor in concern, while the Doctor gave the wand a few practice swishes.

"Oh, don't worry, Mr. Olivander," Jack said, "John's friends actually have to bully him into being normal sometimes." The Doctor glared at Jack again, to which Jack responded with a sunny grin.

Olivander smiled at the interaction between the two boys. "Very well then," he said. "The wand will cost you fifteen galleons."

The Doctor passed over the coins. "Thank you, sir. Umm," he paused, "may I send you owls if I have other questions on wand lore?" he asked.

"Of course," said Olivander as he shepherded the boys out of his shop.

As Jack and the Doctor walked back to the inn, Jack turned to the Doctor. "You were actually polite!" he gasped.

The Doctor hummed in agreement. "He really knew what he was talking about. I appreciate intelligence. Besides, one of his descedents was a companion of mine in my fourth body. Ollie had enormous respect for his great-grandfather. I owe him enough to be polite to the man he worshiped as a child."

"Ah," said Jack. He checked his vortex manipulator. While traveling with the Doctor, it only worked as a scanner and as a watch (Jack would have to fix the time traveling system after the two parted company again). It was 3 in the afternoon. "Now what?" he asked.

"Now, we go into that bookstore," the Doctor pointed, "get distracted by books for a few hours, then go back to the inn, figure out how we're getting to the train station in a few days, and then start doing research in my trunk."

Jack groaned internally. "Sounds fun," he said.

**A/N: Sorry I'm a day late. Life's been hectic for the past 2 days. Anyway, check out pottermore for the wand meanings, I tried to match it as well as possible. Also, side note, the new picture? That's using the system by Shermansplanet. All I can say about it is that if it's really similar to what Time Lords use, they must take forever to write anything. Anyway... Please read and review!**


	7. Chapter 7

Chapter 7

"Oh well, that's interesting!" The Doctor pulled out his sonic screwdriver and started flashing it at the wall. "Space folded over on itself with this wall as the entrance to the bubble created."

Jack rolled his eyes and looked up at the numbers posted on the platforms. 9… 10… 9… hmm. "Doctor, are you saying platform 9 and ¾ is behind this wall?"

"But how? It's not like they have a dimensional manipulator. Humans won't create that until the 52nd century. Even you, Jack, don't have one."

"Doctor…"

"Though perhaps a vortex manipulator, if altered properly, could do it. But then it would be rendered completely useless. The forces needed to accomplish such a task would blow the entire system…"

"Doctor…"

"Don't worry, Jack, I'm not going to experiment with yours, unless you want me to. Besides, even if a vortex manipulator could do it, that's 51st century technology. They shouldn't have it, so the point is moot."

"Doctor!"

"Ow!" the Doctor yelped, rubbing his ear. "No need to shout, Jack." He scowled.

"How do we get to the train?"

The Doctor blinked at Jack. "Weren't you listening?" he stared at Jack as if he were an idiot.

"Don't do that," said Jack.

"Do what?"

"You've got that look on your face."

"What look?"

Jack sighed and ran his hand through his hair. "Never mind. Could you just tell me how we get to the train?"

"Through the wall of course." Jack's eyebrows contracted in confusion. "Come on." The Doctor rolled his eyes, grabbed his own and Jack's luggage and stepped through the wall. Jack had been holding one end of his luggage and thus was pulled along with it.

"Oh," said Jack, looking around at the platform. "Space bubble, right."

"This way, Jack," said the Doctor. He had put down Jack's luggage, and had already started forward to the train. Jack rushed to catch up. According to his wrist strap, they were running fairly late, courtesy of the Doctor's interest in the wall. Hoisting his trunk into a firmer grip, he jumped on the train right behind the Doctor.

The Doctor was looking around in fascination. Jack rolled his eyes, planted his hand firmly on the Doctor's back, and propelled him forward. "We need to find a compartment. I'd prefer an empty one, but for some reason, I can't imagine why, we were late, so there probably won't be an empty one." Jack glared at a completely oblivious Doctor.

The Doctor was still studying his surroundings, so, with a sigh, he grabbed the Doctor and pulled him into a compartment. It was already occupied. Jack rubbed his eyes and looked again. Nope, he was not seeing things; there really was a pair of violently red haired twins in front of him. The Doctor finally deigned to take notice. "Gingers!" he exclaimed. "One day, Jack, I will be a ginger!"

The twins shared a look then stared at the Doctor. "What he means to say," Jack said, "is 'may we join you here?'"

The twins shrugged. "Sure," said one.

"Here, let me help you." The other one got up and helped Jack and the Doctor lift their trunks into the overhead compartment. "I'm George, this is Fred." Fred waved slightly.

"I'm Jack." He looked at the Doctor. The Doctor was still staring enviously at the twin's hair. "This freak of nature is John. John? John!" The Doctor finally remembered his cover name and glanced at Jack. "Say hello."

"Hello. So your hair… it's natural? How'd you get- oof!" Jack rammed his elbow into the Doctor's gut.

"Ignore him. I tend to."

George and Fred traded looks then shrugged. A slightly weird first year was nothing to get upset about. They settled back down and continued doing whatever they were doing before. Jack and the Doctor sat down across from them. Jack pulled out the book for first year Defense Against the Dark Arts. The Doctor started to read his own book. Jack glanced over the top of his book. "You moved along quickly. Is that your last book?"

The Doctor hummed in affirmation. "But… that's the seventh year potions book!" exclaimed Fred.

"I know; I'm horribly unbalanced," said the Doctor. "I had meant to read each year at a time. But I got really stuck in charms. For the most part, it makes sense, but there are some things that seem to defy all logic. And don't even get me started on transfiguration. None of the textbooks for Hogwarts actually discuss theory, and when you read the texts that do have theory, they all assume you already know the basics." He scowled at his book. He absolutely HATED not understanding something, and the entire system was making it impossible for him to gain the knowledge he wanted. The most frustrating thing was that he was positive transfiguration was one of the keys to them getting their adult bodies back.

Fred's jaw dropped. Not even Hermione Granger compared to this first year in front of him. Jack shrugged and sent Fred a sympathetic look. He knew how scary his friend's intellect could seem. Silence fell in the compartment as the two younger boys continued reading. Fred and George quietly started planning some of their pranks for the up coming year. Occasionally, one of them would glance at the boys. Jack calmly paged through his textbook, making decent progress.

John, as they knew him as, on the other hand, tore through his books, finishing every potions textbook he had (including secondary school level material), all the DADA books, _Hogwarts: A History_, a few muggle texts, and was now writing in journal. George, on pretence of stretching his legs, caught a glance at his notes. As far as he could tell, they were naught but overlapping circles, beautiful to look at, but gibberish. By the way John was studying them, though, George thought they might be some kind of code.

Despite the boys, specifically John, being absolutely creepy for first years, George and Fred felt an odd sort of peace come upon them. They filled the compartment just enough so that nobody came in, looking for a seat, and the boys were quiet and private, allowing the Weasley twins to plot and plan without somebody nosing into their business. George had put his notes away and was settling down for a nap when the train started to slow, then came to a lurching halt. "What?" he asked, confused. He shot a worried look at Fred right before the lights cut out.

"Ack!" yelped Fred.

"Shh!" hissed somebody. There was a slight whirring noise, and a bright blue light suddenly illuminated John's face.

"Doctor, are you getting anything?" Jack asked.

George was about to ask whom Jack was talking to when John answered: "There's something… I don't know what. It's sucking in massive amounts of energy though…" The boy's lips pursed. He pointed the light at one of the walls. "It's coming this way." He suddenly spun to face the door. "Somebody's coming."

At that moment, Draco Malfoy burst through the door. "Dementors," he whimpered and threw himself at Fred.

Dealing with a sudden armful of trembling Slytherin, Fred was wholly unprepared for the dementor that entered the compartment just a few steps behind Malfoy. Any happiness he had been feeling left. He was freezing. Horrible memories and thoughts whirled around in his head. Judging by George's expression, his brother was feeling the same way. Malfoy was trying to bury himself into Fred, or so it felt. Meanwhile, there were the two first years…

Jack was swarmed with terrible memories: his brother… working for the time agency… Ianto dying in his arms… his grandson, dying by his hand… Owen… Tosh… the year that never was. The memory of pain flashed through his system. So many deaths, so many tortures. They peripheries of his vision blackened as unconsciousness threatened. The only thing that held off the darkness was the sight of the Doctor.

**This chapter was fun to write. It was also one of the biggest things that slowed me down while writing because I had to wait until my copy of PoA was available so I could be as accurate as possible.**

**Sorry for the cliffhanger (I'm really not that sorry). Don't forget to review!**


	8. Chapter 8

Chapter 8

The Doctor realized he was under psychic attack the moment the dementor entered the room. He threw up every single mental barrier he had, but it was not enough. The creature in the room was powerful and sneaky. Instead of fighting against the unbeatable walls the Doctor had put up, it merely found (or created) a door and entered in that way. The Doctor put up a fight for perhaps five seconds before spinning horribly out of control. Every single terrible memory in his long life hit him at once. Companions leaving (oh Susan… oh Romana… oh Rose), companions dying (Adric, NO!), his screw-up's (I'm sorry, I'm so sorry). But all those paled in comparison to his memories of the Time War.

The Doctor was unconscious before he hit the floor. Even unconsciousness was no reprieve, however, as his mind was bombarded with memories, skewed and distorted into even more horrifying forms by his failing brain. His body started to seize in response to the flood of neurons firing uncontrollably. Attracted to the complex emotions the Doctor presented, the dementor turned to face the Time Lord directly and hunched over him, devouring his mind.

Jack was nothing if not fiercely loyal to the Doctor. It was not at all a happy feeling (in fact, if he analyzed it a little, it was actually kind of sad how much he was willing to give to the man). He full body tackled the dementor. At least, that was the plan. Just as he was going to make contact, a shining white shape collided with the creature, driving it past and away. Moments later, the lights flickered on, and the train started to move again.

Malfoy pulled himself out of Fred's arms and stumbled out of the compartment, not even noticing the other boys in the room. Fred did not say anything. Better for him to be gone. He groped for his brother's hand. George grabbed his hand and squeezed. Only then did Fred breath. Together they looked at the two first years.

Jack had recovered from his attempted tackle and had immediately gone to the Doctor's side. The Doctor was still seizing slightly, though the muscle contractions were lessening in frequency and duration. Jack grasped the Doctor's hand. "Doctor?"

The Doctor's entire body suddenly relaxed, and his entire body became limp. Jack turned to Fred and George. "Help… please," he choked out. The twins looked at each other, silently agreeing on a plan before they both suddenly snapped into action. George ran out the room, looking for somebody more qualified to help. Fred bent down and helped Jack move the Doctor to the bench.

George reentered, almost immediately, dragging a slightly scruffy man. The man understood the situation at once and rushed to the Doctor's side. "Enneverate," he said, pointing his wand him. Nothing happened. The man cursed under his breath then turned to Jack. "He's stuck in memories. He needs to be called out. What's his name?"

"D… John. John Smith," replied Jack, catching himself just in time. "He'll probably respond better to 'Doctor', though," he added. "Everyone calls him that."

The man nodded. He rolled up his sleeves. He took a deep breath to compose himself then shouted out: "Nos redire, Doctor. Noli demorari in tenebris, sed redit ad lucem!" There was a brilliant flash. The Doctor gasped and shot up in Jack's arms. At the same time, the man staggered and fell down. George bent down to help him. "I'm all right," he said, pulling himself to his feet. "It's just a very strong spell," he explained. He went to study the Doctor.

The Doctor had started flailing as he woke, but Jack grabbed at both his hands and held them tightly. "Doctor!" he shouted. That seemed to do it, since the Doctor stopped struggling and focused on Jack. Wild, frantic eyes met worried, scared ones. The Doctor sobbed and threw himself at Jack, pulling him down into a desperate hug.

"They're dead, Jack! They're all dead!" he keened.

"I know, I know, _John_," Jack patted the Doctor gently on the back, emphasizing the name. He needed the Doctor to remember their situation as quickly as possible. It seemed to work, as the Doctor withdrew his arms from around Jack. Still, he folded in on himself, curling up in a ball, crying softly.

The man, satisfied the Doctor was not about to relapse, straightened. "There're others who need me. I'll be back momentarily," he said. "I am Professor Remus Lupin," he added. He nodded and headed for the door. "I'll be right back," he reiterated. He left.

**A/N: Explanation: What Lupin said was in Latin. Use google translate for an exact translation (otherwise, it was basically, 'come back to the light'). There will be a more thorough explanation of how spells work in a few chapters. For now, just understand that the more one focuses on the spell, the more effect it has. By using Latin, Lupin really had to focus on what he was doing, thus the strength of the spell increased exponentially. **


	9. Chapter 9

Chapter 9

Jack sat down and scooted over to the Doctor. "Shh," he said, comfortingly, rubbing the Doctor's back gently. Fred and George watched awkwardly from the other side of the compartment.

There was a knock, and the compartment door slid open again. Professor Lupin entered with several bars of chocolate. "Here," he said, "this will help." He passed one bar each to George and Fred. Jack got two. "And however many your friend can eat, he should have," said Lupin, passing Jack the rest of the bars. Jack nodded in thanks then unwrapped a bar and started trying to coax the Doctor to take it.

A shaking hand reached out from the tight ball the Doctor had curled into and snagged the chocolate bar. It retreated back into the ball. A few moments later, Jack heard a slight murmuring. "Sugar and caffeine providing a sharp boost of energy. Bitterness to shock the system. Perhaps some kind of spell on this bar for additional recovery. I'll have to remember this one." The Doctor twisted in position until he could see Jack. "I need to talk to you," he said.

Jack took a look at the Doctor's tear streaked face. He no longer looked panicked, but he did appear to be trying not to wince. He turned to Fred and George. "Could you guys give us a minute?" he asked.

Both boys leapt up instantaneously. "No problem," one said. "We'll be right outside if you need us," the other added. They exited.

"Doctor, are you alright?" Jack asked, helping the Doctor into a sitting position.

"What do you think?" snarled the Doctor. "With this stupid, tiny, immature brain, I'm completely susceptible to mental attacks. All my barriers are weakened. And my emotions are completely out of control. I've got a raging headache. Half the mental blocks I set up on the TARDIS have been damaged, leaking memories that don't make sense, and on top of all that, my left heart isn't beating!"

"What?!" yelped Jack. The Doctor fixed him with withering glare.

"The noise isn't helping my headache," he commented.

Jack winced apologetically. "Um… what happened to your heart? And how do we fix it?" he asked.

"I need you to hit me, as hard as you can, right here." The Doctor gestured at his chest.

Jack cocked his fist, ready to punch the Doctor. "You're sure?"

"Just get on with it." The Doctor rolled his eyes.

"Here goes something," muttered Jack and punched the Doctor as hard as he could. The Doctor gasped and doubled over. "Are you okay?" Jack asked worriedly as he reached to help.

"Just peachy," said the Doctor as he allowed Jack to gentle him back into a seat. He groaned slightly and rubbed his chest. "That seems to have worked. Really doesn't make sense though."

"What doesn't?"

"At this age, I should not be able to handle only one heart beating for so long. That ability comes with age. It nearly killed me in my third body…" He faded off, lost in thought. Jack shrugged. There was nothing he could say that would have any decent input in the conversation. The Doctor suddenly winced again.

"What's wrong? Is it your heart again? Should I punch you again?" Jack raised a fist.

"What? No. Will you just… go away," said the Doctor. "As I said, memories I had locked down are bleeding through. Migraine. I need to meditate for a bit." The Doctor rearranged himself into a more comfortable position. "You can let the twins back in. Don't mind me." He closed his eyes and immediately delved deep into his mind.

Jack turned and went to the door. "You guys can come back in," he said, looking at the twins. Then he noticed the professor, Lupin, was waiting as well. "Um, is there anything else?" he asked him.

"I wanted to make sure John is alright now."

"Oh, yeah. He's got this neat trick for handling mental problems. He just meditates for a bit and then he feels better." Lupin frowned and glanced over Jack's shoulder to the other boy. "Honestly," said Jack, "by the time we reach Hogwarts, he'll be fine."

"If you say so," said Lupin. "We'll check him getting off the train…" He turned away, thinking. A boy with such bad memories, worse even, he suspected, than Harry's. And he knew how to meditate theoretically well enough to fix the damage of a dementor's attack? Interesting.

**A/N: Rather short, but hopefully amusing. **

**I would like to briefly reiterate, because it has been brought up in reviews again: this is just slightly AU in that JKR did not write the Harry Potter books. **

**You guys are awesome with your reviews, favorites, and follows. I live for this stuff! (Well... not really, but I sure do appreciate it!) So please review and favorite/follow if you are not already doing so!**


	10. Chapter 10

Chapter 10

Lupin had sent a message to Dumbledore explaining the situation. Dumbledore, therefore, had a quick meeting with Professor McGonagall and Madam Pomfrey.

"By all means, pull Harry aside, before he enters the Great Hall to check up on him. But I want the first year boy to be able to attend the sorting with the other children," said Dumbledore. "First impressions are important, both for him and for the other students. Besides, Remus Lupin said that every time he went in to check on the child, he was meditating and was seemingly fine."

"Seemingly fine and actually fine are two different things!" protested Madam Pomfrey. "He could be putting on an act. What eleven year old boy even has the patience to meditate, let alone the knowledge of how to do it?"

"Which is why you'll have a chance to look at him before he even gets on the boat," Dumbledore assured her. "I asked Remus to keep the boy in his compartment on the train until you could look at him. If he's not up to sorting, you can whisk him away to the hospital wing and we can sort him in private later. I would just prefer he is given the chance to be sorted with everyone else."

Madam Pomfrey grumbled but reluctantly agreed to Dumbledore's plan. Even Dumbledore's plans are not fool proof though.

When the train pulled up to the station, everyone started getting up to leave. The corridors on the train were flooded very quickly with students all trying to get off at once. Lupin cursed to himself as he fought through the narrow passage to reach the compartment with John Smith. Really, he should have been there already, but he wanted to check in on Harry one last time.

One burly seventh year accidently shoved Lupin into an empty compartment. Lupin, knowing better than try and fight it, went with the motion and controlled his fall so that he landed on a seat rather than the floor. Sitting down, he put his head in his hands. There was no way he was reaching John Smith before he left the train.

When the train had ground to a halt, and the Weasley twins started gathering their things, Jack nudged the Doctor. There was no response, so Jack pushed him a little harder. Still nothing. Fred was watching curiously to see what would happen. Jack sighed. Well, there was only one thing for it. He brought his hands together near the Doctor's ear and clapped.

One, two, three, four.

One, two, three, four.

One, two, three, four.

Each time he got a little louder. George was watching too, now. The Doctor came out of his mediation all at once. "The Master! What? Ack!" In his attempts to get away from the source of the rhythm, the Doctor fell on the floor. He glared at Jack who was doing his best not to laugh. "What?" the Doctor asked again from the floor.

"We're here."

"What?" The Doctor looked around in confusion.

"You've been meditating for several hours. We're here now."

"Oh." The Doctor rubbed a hand across his face. George and Fred traded a look, shrugged, and left, waving at Jack and promising to see him inside.

"Feeling better?" asked Jack as he helped the Doctor up.

"A bit, not one hundred percent yet, though," replied the Doctor as the two time travelers made their way off the train.

Madam Pomfrey was fuming. Remus Lupin had just informed her that he missed John Smith. She approached Minerva McGonagall's office. Taking a breath to compose herself, she hid her anger and bustled into the room. Potter groaned slightly as she proceeded to check him, teasing him gently as she did so. _One day_, she thought to herself with some amusement, _he might realize that I'm teasing him out of affection and not actually angry with him_. She smirked and forced some chocolate into his mouth.

After making sure he was all right, she left, hoping to reach the first years before they were sent in for sorting. Unfortunately for her, she reached the waiting room the same moment the last of the first years were entering the Great Hall. She could have screamed in frustration, but the doors were not entirely sound proof, and she had a reputation to maintain.

The Doctor was still a bit woozy, but he even as he was waiting, he was recovering. He studied the room they had just entered. There were four long tables filled with students, then a dais with another table where the professors were seated.

He watched with interest as Flitwick, the tiny professor who led them into the room reappeared with a stool and an enormous hat. Moments later, the hat broke into song. While the Doctor's subconscious filtered the song, gathering and analyzing all it had to say, he personally was more interested in how it worked. Perhaps nanobots animating it? No…. A really skilled ventrilaquist? Definitely not. Magic then. What kind?

Before the Doctor could figure it out, Flitwick started calling students up to put the hat on. The hat would sit on the student's head for a few moments, then shout out where the student belonged. The Doctor suddenly paid attention to the analysis of the song he had been ignoring. The hat read minds?

"Jack!" he hissed. The immortal turned to look at him, questioningly. "A while back, I showed you how to block off entire portions of your mind from psychic intrusion, remember?" Jack nodded. "Do it now, anything that would suggest you're more than an eleven year old from this time period." Jack frowned in confusion, then his eyes snapped open wide and he stared at the hat. He nodded again to the Doctor then started concentrating as he shut down portions of his memory.

The Doctor started on his mind as well. As he had told Madam de Pompadour, it was a simple task of imagining doors in front of anything that needed to stay hidden and then shutting it. The complicated stuff started happening when it was a non-friendly force in one's mind. The Doctor was taking no chances. First, he imagined locking the doors. This was hardly enough, though. A skilled mind reader could easily pick the lock or just knock down the door. Carefully, the Doctor started covering the doors, disguising them so that they looked like part of his mental landscaping. By the time he was finished, his mind really did appear like an eleven-year-old human.

He was just completing his final check, when he heard Flitwick call out: "Harkness, Jack!"

Jack hesitated a moment, finishing his own security system, before strutting up to the hat. Everyone in the hall was watching him, and he loved the attention. The Doctor rolled his eyes. _With a head as inflated as his, it's a wonder that hat doesn't fit_, he thought to himself as Jack plopped the huge hat over his head.

The hat took a while to make a decision, much longer, the Doctor noted, than the average for the students. Finally, the brim-mouth opened. "Slytherin!" The hall burst into applause, though the Doctor could detect some confusion. Most students were somewhat perplexed, since Harkness was not a standard pureblood name. George and Fred were specifically confused having met Jack. He had not seemed Slytherin material.

Jack seemed to pick up the mood of the room, and he shrugged and swaggering over to the Slytherin table. The Doctor rolled his eyes; Jack really loved being the center of attention.

The Doctor zoned out again. Like all ceremonies, this whole thing seemed needlessly long and pointless. Out of boredom, he started to calculate the exact coordinates he would need to pilot the TARDIS into geosynchronous orbit around a planet with four moons in a tertiary star system. It can therefore perhaps be forgiven that he missed his name being called… twice.

"Smith, John?" Flitwick squeaked out again. Dumbledore, sitting at his place at the head table pursed his lips. Perhaps John Smith was still ill from the dementor. Suddenly though, a smaller boy at the end of the line looked over at Flitwick.

"Did you call for John Smith?" he called out.

"…Yes," responded Flitwick.

"Sorry," said the boy and trotted up to the Sorting Hat. The entire hall broke out into whispers, discussing the strange boy and his apparent lack of focus.

As the Doctor made his way up to the Sorting Hat, he finished shielding most of his mind. Gallifreyan children, especially those to later become Time Lords, were exceptionally bright, and while the Doctor had no problem showing off his intellect, he felt the Hat really did not need to know the extent of it. Thus, when he put the Hat on, he appeared to be nothing more than a normal genius… if such a thing existed.

**A/N: Woo! Long chapter today. And we've finally reached Hogwarts! I was originally going to post a big, long, farcical chapter poking fun of how it's taken 10 chapters to reach the castle, but in the end, it seemed more work than it was worth (also, it would have thrown off the chapter numbering system...). Anyway, I hope you enjoyed this! Please review!**


	11. Chapter 11

**A/N: Usually I put these at the end, but this is somewhat important, so please read:**

**First off, I'm updating a week early. This will NOT become a normal occurrence. The updates will still be every other week, but next week will not only be insanely busy, but also insanely stressful. So rather than accidentally miss an update, you get this today. The next update will be in two weeks from now.**

**Second... There are over 100 reviews, over 100 alerts, and 80+ favorites! Thank you so, so much! You guys are awesome!**

**Oh, also a brief warning: this chapter has a lot of dialogue from the book. So I guess I should reiterate: I don't own Harry Potter or Doctor Who (duh!)**

**Without further ado, Chapter 11! Enjoy!**

Chapter 11

_Well you are certainly interesting_, a voice spoke into the Doctor's mind.

_Telepathy?_ Asked the Doctor.

_Of a sort_, responded the voice.

_You're the Hat?_ The Doctor felt an affirmative sensation, as if the Hat had nodded at him. _So what's interesting?_

_You are exceptionally bright. _

_ And that causes problems?_ Asked the Doctor. Perhaps he should have hidden more of his intellect?

_Normally I would put you into Ravenclaw without hesitation, you are certainly eccentric enough for it._

_ But?_

_ You would fit better in Gryffindor. _

The Doctor blinked. _You're telling me there is a house meant for quirky, somewhat insane, brilliant people, and I would fit better in the house meant for suicidically brave, stubborn people?_ He received another affirmation. _Have you not gotten the sense of me running away from problems all the time?_

_ Only to regroup, come up with a plan, and fight back_, pointed out the Hat. _All your intellect is directed towards defense of the weak. Running away is, for you, a highly successful strategy. Besides, I get the impression that you frequently run head on to the problem, not away. Also, Ravenclaws tend not to get their hands dirty. Usually, they would rather watch and study than get involved. I do not think you would like that. _

The Doctor shuddered slightly. They sounded a bit too much like the Time Lords.

_If you would really prefer Ravenclaw, I can put you in. I do, naturally, take your opinion into account…_

_ No_, responded the Doctor. _You've been doing this a lot longer than I have. I will submit to your greater experience._

_ Very well, _said the Hat. _In that case, I put you in _"Gryffindor!"

As the hall exploded with applause, Fred and George traded a look. Silently, they both agreed that they were expecting John to wind up in Ravenclaw. Fred shrugged and looked for Hermione. He really wanted to see the two nerds in a conversation. George, interpreting Fred's searching, nudged him and pointed at Ron, sitting by himself.

"Hermione and Harry were pulled away by McGonagall, remember?"

"Ah, right." Fred looked back to the new Gryffindor. He seemed to seriously be considering Percy's invitation to sit next to him. "John," he called, "over here!"

The Doctor spun to identify the voice calling out. He spotted the twins. "I'm sorry," he said to the other ginger in front of him. "I'm going to go sit with your brothers and so you can sit with some first year who really doesn't know anyone." He shot poor perplexed Percy a smile and went to sit with Fred and George.

While talking with some form of authority was attractive, the Doctor felt it could wait until he was no longer woozy from the dementors. Besides, while he had spent most of the train ride either reading or meditating, he already had a sense that these two were both incredibly fun and were definitely valuable, if unorthodox, connections to have.

Jack rubbernecked until he could see the Doctor sitting down next to the two boys they had met on the train. He allowed himself a sigh of relief. The Doctor was brilliant, but he was rubbish at going under cover. He was too eccentric, too clever, and never knew when to stop talking. At least sitting next to the twins from the train, there would be someone who at least kind of knew that he was weird and seemed to accept it.

Jack checked back to the line of first years. The last one was being sorted. The new Hufflepuff was making his way to his table when the doors to the Great Hall opened. Two students slipped in and made their way to the Gryffindor table. "Potter and Granger," sneered one of the Slytherins at Jack's table.

Another boy, the one who had run into Jack and the Doctor's compartment, spoke up: "I heard Potter fainted on the train." Despite the lack of anything humorous about that statement, most of the students at the table laughed. Jack was about to ask what was so funny when the headmaster (Dumbledore, Jack reminded himself) stood up.

"Welcome!" he said. "Welcome to another year at Hogwarts! I have a few things to say to you all, and as one of them is very serious, I think it best to get it out of the way before you become befuddled by our excellent feast." He cleared his throat and continued, "As you will all be aware after the search of the Hogwarts Express, our school is presently playing host to some of the dementors of Azkaban, who are here on Ministry of Magic business." He paused.

Jack shot a concerned glance at the Doctor, who was seemingly ignoring Dumbledore while using a fork to 'write' on the table. Jack guessed it was calculations of some sort. He knew, despite the Doctor's apparent lack of focus, he was hanging on every word. He could not be any happier than Jack at the idea of happiness-sucking fiends wandering around the school.

"They are stationed at every entrance to the grounds," said Dumbledore, "and while they are with us, I must make it plain that nobody is to leave school without permission." With interest, Jack noticed that the Weasley twins were conferring with each other and one other boy. He wondered what about. He would have to ask the Doctor later. "Dementors are not to be fooled by tricks or disguises—or even Invisibility Cloaks," he added. Jack wondered if Chameleon Circuits and Perception Filters would work. To his chagrin, he was so busy trying to figure it out, he actually missed the next few lines of Dumbledore's speech.

He did not zone back in until he heard clapping. Looking around wildly, he realized it was because Dumbledore had just introduced Professor Lupin, the man who had helped them on the train. Jack joined the applause loudly and enthusiastically. Interestingly, he was one of the few at his table to give anything more than a condescending slow clap.

"As to our second new appointment, well, I am sorry to tell you that Professor Kettleburn, our Care of Magical Creatures teacher, retired at the end of last year in order to enjoy more time with his remaining limbs." Across the room, Jack noticed the Doctor musing at his right hand. Jack grinned, guessing what the Doctor was thinking about. "However, I am delighted to say that his place will be filled by none other than Rubeus Hagrid, who has agreed to take on this teaching job in addition to his gamekeeping duties."

The table the Doctor was sitting at exploded with applause. At Jack's table, most of the students were staring at each other aghast, too stunned to even try to clap. Jack's eyebrows knit together. So far, everything he saw suggested that Slytherin and Gryffindor were opposing groups. He wanted to figure out why. Hopefully, it would not interfere too much with his and the Doctor's communications.

"Well, I think that's everything of importance," said Dumbledore. "Let the feast begin!" Food appeared on the table, juice appeared in the pitchers, and Jack realized that lunch had been several hours ago. He dug in with delight.

**A/N: Why are you reading this? Everything important was stated above :P**


	12. Chapter 12

Chapter 12

For the most part, Jack focused on his food. He could not help (nor would he ever want to) overhearing the conversations around him. "So, yeah," said the boy who had come into the train compartment. "Potter totally fainted!" There were chuckles up and down the table. Jack raised an eyebrow. Lot of false bravado in that kid, he thought, if how he acted on the train versus now was anything to go by.

The conversation moved on, and Jack began collecting names. The boy from the train was called Draco Malfoy. His friends were Goyle and Crabb. The three other boys in his own year were Richard Prince, Leslie Lancaster, and Achilles ("Call me Ash, everyone else does") DeGuiche. There were some girls his year too, but the conversation moved before he could catch their names. Oh well, he would figure it out eventually.

"What about you?" Someone nudged him. Jack looked up. The conversation had drifted into genealogies. Most of the students seemed to know each other at least by name and were trying to figure out if and how they were related. Slytherins seemed fairly obsessed with family histories. "Harkness isn't really a pureblood name…"Oh dear, thought Jack. It's a status thing. He sighed.

Rule of the Time Agency number 5: avoid lying when possible; it makes everything more complicated. Sub-rule A: misdirection will generally work, but only if you're subtle about it. Sub-rule B: give them a half-truth and let them assume whatever they want. *See notes on assumptions, appendix V. Sub-rule C: if you must lie, keep it simple. Appendix V summary: Assumptions are great, as long as you're not the one making it. If the person you're trying to fool makes an assumption go with it only as far as you are able to maintain it; don't allow them to overstep your abilities to match their expectations.

"Well, maybe not in Britain…" he let himself trail off. He considered emphasizing a more American accent, but decided that would be pushing it, and then he would probably have to maintain the accent throughout the school year. Either way, he got the desired results.

"Oh…" said several people around the table. "What brings you to Britain?" asked one of the girls from his year.

"Well…" Jack cast about for plausible ideas. "My immediate family isn't able to look after me right now for various reasons," as in he killed their child and they do not want to even look at him, they tried to blow up Torchwood headquarters, or they do not exist yet and will not for another 3000 years, "so I've been living with some really close friends." He chuckled. "Sometimes they seem more like family than my real family does." None of it was a lie. Jack was proud. He had not had to spin a half-truth on the fly like that in a while. It was good to know he still could.

"Do we know any of them?" asked another kid.

Jack paused. Obviously, they did not like Gryffindor very much, but it would be a good excuse for why he was always hanging out with the Doctor… "John Smith, over there." He pointed over to the Gryffindor table.

"You're friends with a Gryffindor?!" squealed the girl who asked why he was in Britain.

Jack shrugged. "Didn't know he would be a Gryffindor before today, and I've known him for years. Besides, I honestly thought he would be a Ravenclaw. He's certainly smart enough to be." The excuse seemed to work well enough for the moment, as the conversation drifted off into another topic shortly after.

Jack sighed with relief and went back to his food. After dinner, the first year students were escorted to the dormitories. Out of the corner of his eye, Jack saw the Doctor being led out one doorway, in the opposite direction. The Slytherins were led downwards, towards dungeons. A password was given and they entered a dimly lit, austere, proud room. "So welcoming," Jack said under his breath, sarcastically. Ash, standing next to him snorted.

One of the prefects pointed out the first year dorms. Jack followed his classmates up. There were four elaborate beds set up in each corner of the room with each student's trunk next to each bed. Jack's bed was opposite the door, on the left side of the room. His trunk was next to Ash's, who was on the left side but closer to the door. Jack shared a quick smile with the boy before getting in his bed and drawing the curtains.

Ash glanced at the other two boys and shrugged. Perhaps he was just extremely tired…they got ready for bed quietly, figuring Jack was already asleep. Jack was not, in fact, asleep, but was on his back, staring up at the ceiling, thinking about the day.

The train ride had been boring right up until it became terrifying. Knowing how the dementor had affected him, Jack could barely imagine what it was like for the Doctor. But he seemed all right now…

Jack's mind skipped forward to dinner. He had taken a very backseat role in the conversation. He could argue that it was because he was information collecting, but it still seemed very much unlike him. Unless it was because his brain was undeveloped? He frowned. He did not like the idea of being different than usual. He would have to talk to the Doctor. Until then, he would make a conscious effort to be more extroverted.

He heard the other three boys get into their own beds and go to sleep, but he made no move to get ready for bed himself. He was not quite tired yet. Even in his new state of 'prolonged regeneration', as the Doctor called childhood, he still did not need a full eight hours; more like five or six. He sighed inaudibly. If he had some way of guaranteeing the curtains drawn about his bed were sound proof, he would consider calling Gwen. Or he could start a diary…

The hell with this, Jack finally thought to himself. Even if he was not tired, he could force himself to sleep: a souvenir ability from the Time Agency. He rolled over, punched the pillow into a better shape, and willed himself to sleep. His last conscious thought as he drifted away was that oral hygiene was for sissies.

**A/N: I survived last weekend and thus we are back on schedule (alas, I have not typed a new chapter yet. Don't worry though, I'm sufficiently ahead that it shouldn't matter). **

**A few people have asked why Jack's in Slytherin. Here's my response verbatim: I put Jack in Slytherin because, even though he is reformed, he is still a con artist. He's sneaky, he's clever, he knows how to make social connections (even if said connections are people who hate him). He loves a good challenge and loves keeping everyone guessing. Perfect for Slytherin. Also, the tension between having the Doctor in Gryffindor and Jack in Slytherin was too interesting to pass up.**

**In other news, I really, really love lampshading. **

**Please review! :)**


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